GARDENER'S MAILBAG

Dear Neil: I’m used to my magnolia trees shedding leaves in the spring. We’ve had them for 40 years, and this is the first time they’ve continued dropping leaves this long. Why would that be happening?

Every year is different. I was just noticing how abruptly my own two magnolias quit shedding leaves onto our deck and yard just a week ago. I’d guess that the cold weather last winter and the hot, dry weather through the first half of this summer have to cause it.

Dear Neil: We enjoy hydrangeas and have planted two this spring. One’s pink flowers and the other’s blue flowers are turning green. Why is this happening?

What you’re calling flowers are actually floral bracts – modified leaves, along the same lines as dogwoods, poinsettias and bougainvilleas. They start out green, turn colors, return to green and then turn brown and crisp. What you’re seeing is normal behavior. Trim them off when they’re no longer attractive to you.

Dear Neil: When are pomegranates mature enough to harvest?

Texas A&M fruit specialists tell us that they will mature in September and October, depending on the variety. When ready for harvest they will have a metallic sound when tapped lightly. They do not continue to ripen after they are picked, so leave them on the plants until you’re sure they’re ready. Harvest one and open it up before you harvest any more.

Dear Neil: What could be wrong with my live oak?

Almost half of its top has turned brown. The tree people I’ve called haven’t been able to help.

Look at the interface where the dead branch intersects with the healthy growth. You may find that a squirrel has sharpened its teeth there, or there may have been some other type of damage. If the dieback isn’t advancing beyond this location, that’s where you’ll find the source of your trouble. If it’s been brown for more than a few weeks, it’s not going to green up again and you might as well prune it out. You may be able to figure out the source of the problem as you do.

Dear Neil: I planted one daylily nine years ago. It has only bloomed once in all of that time. Why might that happen?

This looks more like a crinum lily than a daylily. It looks like it needs to be moved this fall to a raised bed filled with really rich planting soil. It appears to be growing in local topsoil without a lot of bed preparation. Both crinums and daylilies will thrive if they’re given a really good soil mix, a steady supply of moisture and half a day or more of sunlight.

Dear Neil: My wife and I have different types of milkweeds growing in our native wildflower meadow. This year we’re seeing a lot of yellowing and leaf drop. We’re also seeing no caterpillars or aphids that normally congregate on them. We have not used pesticides or weedkillers. They’re in almost full sunlight. What might be causing this?

The plants look dry, and they may also be lacking nitrogen. One of them looks like there might be a virus involved, but I wouldn’t bet the store on that diagnosis. As for the insects, I do not have a good answer. The fact that the plants are not growing vigorously might account for it.

Dear Neil: What is the best soil mix for a raised garden bed that is 15 inches deep? It’s 12 feet by 2 feet.

I would begin by rototilling the native topsoil 4 or 5 inches deep. I would then bring in probably 8 inches of a sandy loam topsoil, but I’d make the vendor guarantee that it did not contain nutsedge (“nutgrass”). I would add 2 inches of sphagnum peat moss, 2 inches of well-rotted compost and 1 inch each of rotted manure and finely ground pine bark mulch. Rototill all of that with a rear-tine tiller to blend it into the native topsoil and you’ll have a garden soil almost like potting soil.

Dear Neil: Our young pecan tree suffered damage after being sprayed for pecan casebearers. It does not have any pecans. Two older trees also have some damage. What might have caused this?

Your photos are thumbnails and were taken from a distance. It’s hard to tell for sure, but it looks like the leaves have been scorched. I noticed how dry the grass is around the one tree, so I have to wonder if drought might not have played a part. It’s also possible the sprayer was contaminated with herbicide or that the insecticide might have been mixed too strongly. I can only guess. I would suggest keeping all three trees watered deeply the balance of the summer. Hopefully they’ll rebound by fall.

Dear Neil: I repotted a bougainvillea hanging basket into a deep pot and it has stopped blooming. How can I get more flowers?

Bougainvilleas bloom best when they’re slightly rootbound. Repotting gave it root room and encouraged new leaf and stem growth. They also bloom best coming out of dormant times like winter and summer. It’s typical for them to have a nice round of blooms in September and October.

Have a question you’d like Neil to consider? Mail it to him in care of the Wise County Messenger, P.O. Box 149, Decatur, TX 76234 or email him at mailbag@sperrygardens.com. Neil regrets that he cannot reply to questions individually.

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